174 resultados para 1995_03251530 TM-41 4501504


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The diffusion rates of seven ferrocene derivatives have been estimated in polyelectrolyte PEG . LiClO4 by using non-steady-state chronoamperometry. The D-app of ferrocene derivatives increases with temperature, and the dependency of D-app on temperature obeys the Arrhenius equation. The D-app of ferrocene derivatives decreases with increasing size of electroactive species. The Delta D-app values of D-T>Tm and D-T T-m in the polyelectrolyte. On the other hand, the diffusion behaviour of ferrocene derivatives is qualitatively analyzed by using cyclic voltammetry. Copyright (C) 1996 Elsevier Science Ltd

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MCM-41 zeolite and Tron (II)-Phen/MCM-41 zeolite have been prepared and characterized by XRD, IR, NH3-TPD, HET and UV-Vis. The Iron( II)-Phen/MCM-41 zeolite+30% H2O2 system is capable for catalyzing hydroxylation of phenol.

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MCM-41 mesoporous molecular sieve and iron(II)-Phen/MCM-41 have been prepared and characterized by XRD, IR, NH3-TPD, BET and UV-Vis. The iron(II)-Phen/MCM-41 molecular sieve + 30% H2O2 system is capable of performing hydroxylation of phenol.

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MCM-41分子筛是最近美国Mobil公司开发出的一种新材料,其孔径范围在2.0~25nm之间,具有较大的Si/Al比和大的比表面积及孔隙率,孔道大小均匀.其对弱极性的环状及芳族化合物具有较大的吸附能力.自这种新型分子筛合成以来,才开始应用于石油炼制及烯烃裂解,歧化的研究.至今还没有关于将MCM-41作为载体,用于负载金属配合物催化剂的报道.本文利用自己合成的MCM-41分子筛作为载体,制成了负载铁的1,10-菲咯啉配合物催化剂(简记FePhen/MCM-41),并将其应用于苯酚的羟化反应,发现其对苯酚的羟化反应具有较好的催化性能.1 实验部分1.1 FePhen/MCM-41的制备将参考文献[3]制得的MCM-41分子筛,取5g放入200mL0.05mol/L的[Fe(Phen)_3]Cl_2乙醇溶液中,室温搅拌24h,抽滤,所得固体用乙醇洗涤3次,以除去MCM-41分子筛表面和孔道内结合不牢的金属配合物.利用原子吸收光谱分析仪,测得负载催化体系中铁元素的含量为0.65%.1.2 MCM-41分子筛及FePhen/MCM-41的表征

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研究了水热法合成晶体,浓度配比、生长温度对晶体生长习性的影响.合成了一系列化学计量比的Y_(1-x-0.3)Er_(0.3)Tm_xP_5O_(14)(x=0.01~0.1)晶体,观察和分析了晶体的缺陷及成因,测定和讨论了晶体结构.

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本文制备了La,Ce,Pr,Nd,Sm,Eu,Gd,Tb,Dy,Ho,Er,Tm,Yb,Lu,Y等十五种稀土与2-乙基己基膦酸单(2-乙基己基)酯的固体配合物,测定了4000-100cm~(-1)的FT-IR光谱,对其主要红外光谱吸收带进行了归属。指认150cm~(-1)为Ln-O键的伸缩振动带,250cm~(-1)附近的谱带为COPO,CCPO骨架扭曲振动与Ln-O键的耦合振动带。结果表明配合物为多聚体系,PO_2与稀土离子可能为桥式配位形式。Ln-O键基本上为离子键。

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Manganese-modified mesoporous MCM-41 molecular sieves were synthesized at the absence of alkaline metal ions under mild alkaline condition using cetylpyridinium bromide surfactant as a template, and characterized with X-ray diffraction, N-2 adsorption, transmission electron microscopy, electron spin resonance (ESR), and nuclear magnetic resonance (NMR) spectroscopies. The synthesized MnMCM-41 has a high pore volume of 1.30 cm(3) g(-1) with a corresponding surface area of 1510 m(2) g(-1). The ESR and Si-29 MAS NMR spectra revealed the presence of framework manganese ions in either the as-synthesized or calcined forms. (C) 2002 Elsevier Science B.V. All rights reserved.